[Closed] Solar, recent energy hikes and feed-in tariffs

Feed in tariff is closed, no new contracts. It's done its job, which was to help get PV panel production volumes up enough to get prices down. It's now just export tariff, ie, being paid for the electricity you supply to the grid, not what you generate. Rates vary depending on the company, see https://solarenergyuk.org/resource/smart-export-guarantee/ I think you'll need a smart meter that measures the outgoing.

The export rates are mostly a lot less than you pay for supply, so the bulk of the payback comes from not having to pay for all your electricity. A battery can help there as you can store what you don't use when it's sunny and use it later rather than exporting. A battery might (depending on the company/tariff) give you the opportunity to buy power from the grid at slack times and sell it back at peak times.

There may be websites that will work out the payback (but may be trying to sell you something), or you may just need to collect data and work it out. PV panels should work for 20-25 years, but inverters may need to be replaced or repaired before that.

I've got to say that even with our suboptimal roof I'm looking at it again given that dumping the excess production into the EV and mixergy cylinder soon makes quite a saving given it looks like electric is heading north of 20p/kWh.

its not 20-25 years pay back monatary wise these days . Based on numbers last october Spot rates not accounting for inflation or rate rises as we are currently seeing. I was lookign at just under 11 years payback without accounting for SEG but accounting for 1 Inverter replacement. - Edit - of course will depend on your roof .... mines 5 degrees off South - to the easy and its also at 50 degrees.

4.14KW installed was £4500 this year.

10 years ago my quote was £13000

Carbon pay back on the other hand is closer to 1.6 years for domestic panels.

They have been in since 21st july and have generated 916KWH - Which has halved our electric bill and thats at 16p/KWH..... with peak generation mid summer at 25KWH/day -

the hardest part i found was getting a non flybynight installer - ended up with AES solar in forres. lots of one man bands and traveling companies that looked ready to disappear at the first sign of an issue.

Dont underestimate how hard it is to use the power usefully (unless you have a hot water tank you can fit an immersion controller and use it that way) - we dont / cant easily retrofit so are considering a battery for when we are back to the office AND IF our monthly average generation hits a certain number over winter ..... im sceptical given we are in Aberdeen and its dark on average 26 hours a day in winter but its certainly taking the strain over summer.

The export rates are mostly a lot less than you pay for supply, so the bulk of the payback comes from not having to pay for all your electricity

This - and with electricity prices going through the roof they're looking more attractive.

BUT you have to be smart about how you use them - don't go thinking that you're going to charge your car and get a cylinder of hot water with some to spare..... its not going to happen!
I've got two 4Kwp systems and over the 10 years we've had them the average summer day production is about 16Kw with highs of about 25kw. Last week we got an average of about 10Kw/day - so it's not massive now and it will tail off as the weeks go by.
That said it's still heating hot water that would otherwise be using oil and saving some money.
In the summer you generally use less power so some of your production is going to go to the grid unless you have a battery system - but they're big money and im not convinced about the economics of them atm.

All that said I've been musing about whether I could add some south facing ground mounted panels to boost the winter production.

AND IF our monthly average generation hits a certain number over winter

Do you want the good news or the bad news?
Our south facing 3kwp system in N Wales averages about 3kw/day in November/December!! Our 4Kwp system in Chester is East/West facing is great in the summer as it starts producing earlier and finishes later than a S facing system - but in the winter it suffers and in November/December it will only produce an average of 2kw/day!

which is why i have not yet bought a battery.

Itll become clear once the data logger has recorded a winter what the pay back for my local area will be .

I have a theoretical base line number in my calcs at the moment and if it reaches that then im golden - below that is a sliding scale of worthyness ..... but with electric prices heading north fastthe calcs are skewing all the time.

I had solar fitted in May this year. 5.2kw for £5k. I think of it like this: I will generate 4300 units a year for the next 15 years I intend to stay in the house. Thats 8p per unit forward purchased. What is the cost of elec today 19p? I am using 2/3 of my generation because we have an EV thats still 12p if I export the other third without income. As it is I am on Agile Octopus and the rates at the moment are about 16p..

I put the payback period at a bit less than a decade with EV

Mid June we produced over 30kwh on several days, and charged the car purely on solar for a lot of the month 🙂

we are in Aberdeen and its dark on average 26 hours a day in winter

😂

We had solar fitted last November. Worst time of the year to see the benefits of it. It came in to its own though March this year, when we were able to turn off our oil boiler. We had a solar boost fitted, so before paying in it'd heat our hot water first. There have only been a handful of days so far where we've had to top up the hot water with the boiler.
It'll mean we only need to fill up with oil once a year, which considering how much it cost this time, its a considerable saving (around £500 a year). We are also looking to get out export payment soon, again around £500.
Since November we have generated around 2700kwh. We aren't in a perfect south facing position and have trees that block with winter sun, but it isn't bad. It has probably saved us around 1/3 off our bills so far.
The panels we have are JA Solar 380W Mono MBB Percium Half-Cell. 9 of them. Cost with inverter was 6k.
We used a local installer that had a good rep.

Itll become clear once the data logger has recorded a winter what the pay back for my local area will be .

I'd share my historical pvoutput data with you but it seems you need to be registered.

We are also looking to get out export payment soon, again around £500.

How do you get that number?
Yours may be wildly different but I get 3.95p/kw, so on an annual production of about 3200 Kwh (you'll be very similar) I'd get about £65!!
or do you mean generation tariff as well as export tariff?

Ah sorry, I did mean around 60. I am sleep deprived at the moment, so muddled my oil bill.

Just done some digging we get 4.12p/KWh generation, plus 5.38p/KWh for export with assumption that 50% is exported (no smart or export meter). 5 panels (total 1.4KW) which generate approx 1150KWh per year on a south facing roof in North Lakes. Supply and install as part of new build house was £2400. We run an air source heat pump, with electricity being the only energy source for family of 5 (inc 3 teens!), so almost certainly don't export any.
Pay back will be 10 years, with 15 years FIT agreement after that. Saves approx £180/yr in elec and FIT pays approx £75. With more roof space we could have tripled this with 4KW install.

Boxelder- who was your installer? Also north lakes and looking at possibilities….

Cheers, Tom

All, please can we use correct units!

Power is measured in kilowatts, which is kW for short
Energy is measured in kilowatt hours, which is kWh for short

Not kilowatts per hour, or kwp or any other nonsense, just kWh.

It's super easy to do the math, for example

10 kW for 1 hour is, rather obviously, 10 kWh ie 10 x 1

Insolation peaks at around 1.2 kW/m^2 in the UK on a clear summer day at noon, but pannels are only around 20% efficient at converting light into electricity, so a typical solar panel, measuring about 2m x 1m (ie an area of 2m^2), puts out a maximum of approx 400watts or 0.4kW assuming it was perfectly aligned to the sun at all times, which it won't be.

Just a word of warning if installing PV panels for charging an EV, having fallen foul of this myself:

My EV charger currently needs to be able to draw at least 6A to charge our car. My panels produce about 4.25A maximum on a sunny day. So my plan of charging the car from the panels won’t happen until I replace the panels with some more efficient ones (assuming that there’s enough of a performance improvement).

This wasn’t something I knew about and I spent quite a few days wondering why my “solar charging” setting didn’t click on to charge during sunny periods.

Oh well, my calculations didn’t depend on it, just would have been nice.

Not kilowatts per hour, or kwp or any other nonsense, just kWh.

I agree with you on kW, kWh, but kWp is not nonsense, it's a real thing in solar PV - it's kW peak, or what your panels are capable of. I'm not sure whether it takes account of the orientation or whether it's just the manufacturer's figure for optimum angle, but it is a genuine and relevant abbreviation.

Our system will have been installed 7 years next week, generation meter shows 25566kWh. i.e. about 3650kWh per year. Its about a 4kWp system, facing just west of south, North Yorkshire, with no shading.
Most of its output goes to hot water, oil boiler has been used for hot water <10 times since mid March.

We bought our house 2 years ago and is two semi’s knocked into one, the south facing roof has panels over the size of half the roof. We were a little unsure what to do at first but when we inquired it was a FIT tariff and we essentially get around £300 a year back from NPower for elec we generate and the panels of course lower our elec bills too, always put things like dishwasher on when it’s consuming solar and not when taking from the grid. Going to get them cleaned as we have no idea if they’re as efficient as they could be or if anything’s broken etc…

So looking at this it still seems like were better off getting energy from the grid?

Going to get them cleaned as we have no idea if they’re as efficient as they could be

probably pointless